Lecture 9 Circulation

Question 0

WHat percent of blood is in systemic vs cardio pulmonary ?

Answer 0

16 % of blood volume is in the heart and lungs.

84% of blood volume is in the systemic circulation.

Question 1

• Systemic capillary pressure varies from ___ mm Hg to ___ mm Hg.

Answer 1

35

10

Question 2

within the systemic system, what percent of blood is in the veins, arteries and arterio/capillary regions?

Answer 2

• 64% veins, 13% arteries, 07% systemic arterioles and capillaries.

Question 3

what is the volume and pressure difference of blood, between the cardio and pulmonary systems and why?

Answer 3

Volumes are the same, b/c what comes in must go out b/w these.
Pressure is much lower in the pulmonary due to increase area.

Question 4

Equation for Velocity of blood flow is ?

Answer 4

Velocity= Flow / Area
flow = volume/time or cm3/sec
so when you divide flow by Area (cm2) you get cm/sec or Velocity.

Question 5

TQ!- What are the three basic principles that underlie all functions of the circulatory system?

Answer 5

• Rate of blood flow to each tissue of the body is almost always precisely controlled in relation to the tissue need.
• The cardiac output is controlled mainly by the sum of all the local tissue flows.
• Arterial pressure regulation is generally independent of either local blood flow control or cardiac output control.

Question 6

Ultimately, Cardiac Output responds to the demands of the ______ .
B/c flow rate is directly responding to this.

Answer 6

Tissues.

Question 7

•If arterial pressure falls below 100 mm Hg, The what system jumps? and what things happen?

Answer 7

The sympathetic nervous system:
•Increase force of heart pumping.
•Constrict large venous reservoirs.
•Generally constrict most arterials
•Kidneys play a role

Question 8

Flow through a vessel can be calculated by _____ law, which is ?

Answer 8

Ohms law
F= P/R
Flow = Pressure/Resistance

Question 9

Overall blood flow of an adult at rest is referred to as what? and is what V/time?

Answer 9

5000 ml/min

cardiac output.

Question 10

streamline flow is know as ____________ flow.

T/F Velocity is consistent from inner to outer layers in a vessel?

Answer 10

laminar

false, higher velocity in the center layer

Question 11

Re = Reynolds number = measure of the tendency for what?

what is the EQN?

Answer 11

for turbulence to occur
Re = v d p / n
velocity x diameter x density / viscosity

Question 12

What is the range in PRU (peripheral resistance units) for vessels… from being completely dilated to completely constricted? (so lowest to highest resistance of systemic circulation is what this tells you )

Answer 12

.2 - 4 PRU

Question 13

How is your PRU Calculated? and what is it?

Answer 13

Peripheral Resistance Unit - measure of resistance
simply rearrangement of your F =P/R equation to
R = P/F (pressure/flow) mmHg/(ml/sec)

Question 14

For calculating the resistance, Watch out when looking at change between 2 points. What must be done to calculate the pressure?

Answer 14

You must take the difference of the 2 points where pressure was taken and use that difference as your pressure, for your Resistance equation.

Question 15

Poiseuille’s Law determines what? and the equation is? be able to define each term and MORE SO, know what Happens if you were to change the variables like radius?

Answer 15

Conductance (unfortunately labeled as F)
=3.14 x change in Pressure x radius^4/ 8 x viscosity x Length
=3.14 x delta P x r^4 / 8 x n x l
and yes can also be 1/Resistance

Question 16

For Conductance, you must know what is inversely (denominator) and directly (numerator) proportional? so what variables are direct/inverse for Conductance (F)?

Answer 16

Direct: pressure change & radius
Inverse: Viscosity (n) & Length (l)

Question 17

Branching of blood vessels create circuits in Parallel or series? this branching therefore increases or decreases the resistance?

Answer 17

parallel

Decreases 1/R + 1/R

Question 18

Does removing and limb or organ such as a kidney, increase or decrease vascular resistance?

Answer 18

It increases total vascular resistance
which is due and and reason for :
accompanied, decrease in Blood flow and Conductance.

Question 19

• Hematocrit of adult men ≈ __?; adult women ≈ ___?;

* Viscosity of whole blood at normal hematocrit ≈ ___?;

Answer 19

42 and 38

viscosity 3

Question 20

The viscosity of blood plasma (w/o RBCs) = always ___ that of water.
This difference from the Hematocrit is b/c hematocrit contains your RBCs and varies. Normal hematocrit viscosity is what?

Answer 20

just plasma = 1.5 and doesn’t change.

whole blood = 3, and changes due to RBC count.

Question 21

local Autoregulation of blood pressure only occurs between pressures of __ and ___ .

Answer 21

75 and 175

Question 22

Sympathetic Stimulation and Sympathetic inhibition each do what to net arterial Pressure?

Answer 22

Stimulation increases arterial pressure and inhibition decrease